mx842
Platinum Member
- Joined
- Feb 26, 2011
- Messages
- 853
- Location
- Richmond Va
- Tractor
- Kubota L3301, PowerKing 2414, John Deere 316, Gravely ZT HD 52
mx,
Regarding plumbing the HX to the water heater: The HX is horizontal and it doesn't matter which line is in or out, but plumb the out to the top of the tank with as little restriction as possible and an up-slope all the way. This will help the thermosyphon affect and, during a power failure, will circulate some water. Assist it with a pump to get the maximum BTUs to your tank. The 007 should be fine for this duty. Use the 3/4" port on the side of the tank near the top, typically, this is the pressure relief port, as the return from the HX.
TEE the output to your floor pump at the same upper side outlet of the tank, where the HX line ties in. Simply screw a brass or galvy tee on a short nipple sticking out of the tank fitting and plumb each line to it. Return the floor loop to the cold inlet on top of the tank. Pull the dip tube out of the cold inlet fitting and set it aside. Put an automatic air vent on the hot outlet. If you insist on an auto fill system, tie it in at the cold tank inlet with another tee.
I suppose the best flow pattern would be to place the HX pump on the bottom line pumping away from the tank toward the HX. Place the floor on the line from the upper side fitting tee, pumping toward the floor. Return it to the cold top fitting as mentioned.
All of this will tend to move air to the tank and get it out of the system. It will not inhibit thermosyphon.
Install tees on the supply and return lines to the floor. One just before the pump, which is pumping toward the manifold. And one after the manifold on the return line to the tank. Connect these with a 3/4 pipe and a ball valve. This will allow you to throttle a bypass and control the supply temperature somewhat. It also reduces restriction in the floor loop. You'll still get all the available energy to the floor, but you'll avoid scalding temperatures and you'll help the pump purge the air. A bit of manual adjusting of this ball valve will get you find the right setting. Probably 1/2 open for starters.
Install a ball valve on the return line to the tank from the floor. Preferably, near the tank. Then tee in a hose bib right before this valve (on the manifold side). You can then close the valve and open the bib to manually purge the floor loops. This will help you get it all started and force out any air.
Again, look carefully at the manifold to make sure you have the loop restrictors fully open. Very important.
Man!! I wish I had seen this before I piped this thing up. Sounds like I still have some work to do. When I asked this question I had two 20 ft sticks of copper tube, one 1" and one 3/4 and a bunch of fittings. I used that all up the first time then when I re-piped it. Then when I took the mixing valve out I re-arranged the whole setup re-using what I could save. I was thinking about teeing off the top port fitting like you just suggested but I wasn't sure if that was right or not. I instead used the two side ports on the tank where the old heating elements were. I plumbed the top heating element port out to the supply for the loops and the bottom one I used for the return to the HX. Thought being that these are 1" ports and I figured they would be less restrictive than using the 3/4 ports on the tank. I have the pump on the hot side of the HX and it goes to the top port where the T&P valve was. I moved the T&P valve to the hot top port of the tank.
I have a 4 way cross tee piped into the bottom drain on the tank. I came out of that with a boiler drain valve in one port and I sent the return water from the loops in to one of the other ports. I had made up this contraption out of 3" copper I had laying around that I was going to use the other port of the 4 way that I could use to add chemicals to the system without having to shut everything down. Right now that is plugged off, I installed it the first time I re-piped it but removed it when I took the mixing valve out. It looks like I need to go back to the supply house for another stick or two of copper and another box of fittings. I did fire it up last night and it seemed to work pretty good though the way it is.
I found a couple of old aqua stats that I took off an old boiler a few years ago and I put one in the HX to control the 007e. this one has a differential lever on it that you can set. I set the control to cut the pump on at 180 degrees but with a 30 degree differential and that worked pretty cool. Of-course by the time it got up to the 180 mark I had hot water already passing through the pump and going into the tank but it did speed things up once the pump turned on. The biggest problem I still have is that I'm not getting the flow I need through the loops.
The Taco 1/8 HP pump I figured would do the job but I guess it's just not enough. I finally fixed that pump and got it to stop leaking. I took it apart three or four times and put it back together and finally I got it to stop leaking. I had put a new seal in it with new gaskets and I still don't know what fixed it but it seems to be ok now. However when it starts it still squirts a little water out of the oil hole but stops pretty quickly once the pump has come up to speed. I'm still thinking I have some air somewhere that needs to work it's way out.
Another thing I noticed is that one of my air bleeders gets water logged and dumps water all over the floor. It's one of those copper looking things that looks like a small water tower and I just bought it. What would cause one of those to get water logged like that?
I may leave it like I have it now and re-do it like you suggested later just to see what it does. There are a couple other things I want to change but it's starting to cool down now I probably ought to leave it as it is for now and do it all over again next summer.